Malicious PDF — malware analysis report

Static analysis result for SHA-256 5428fe90a3d7a23a…

MALICIOUS

PDF

70.2 KB Created: 2021-06-09 12:59:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: f64fbb61724d65a1cebfc33611c2ef2d SHA-1: d081d4a9d1d1e2e4cd5b0f089f7ed9fe29893014 SHA-256: 5428fe90a3d7a23a35492d9f96cb9888af24b5b52f4450e1f9c5b5d2545d9357
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was flagged by ClamAV as a phishing trojan and by an ML classifier with high confidence. It contains numerous embedded URLs pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be a lure related to educational content, likely to trick users into clicking the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://laborke.ru/uplcv?utm_term=writing+linear+equations+from+graphs+pixel+art+answer+key PDF link annotation
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/97a1c419f32db2a151d4bc38b17358c1/jaxolaliwufozetodevujafu.pdfIn PDF document text
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/265a1f76663127e4226ab6fe8c1dfb07/sazoke.pdfIn PDF document text
    • https://www.plsok.com/wp-content/plugins/super-forms/uploads/php/files/ec1e37739bde7e953f41f8a2500669df/kinukob.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608aab06df7c4---75310137818.pdfIn PDF document text
    • http://elonsummerstorage.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607409d206bab---66516801742.pdfIn PDF document text
    • https://investainternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ce45d8169b---poranob.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609854d1896d1---28975291228.pdfIn PDF document text
    • https://soechi.id/userfiles/file/28873387985.pdfIn PDF document text
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/8stfg3peuu9fpbhvhsvdvpen5v/daziparavugop.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1609a4a22acbf4---18631875572.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/2bce9e2b89a2c1f188cff3a2ea8459f1/nuzepifotuwesikefukus.pdfIn PDF document text
    • https://misionesmedellin2030.com/wp-content/plugins/super-forms/uploads/php/files/4qlbdcghgstqk7m4gj21u7cfnh/wipimid.pdfIn PDF document text
    • http://accessprecision.com/userfiles/file/37118650104.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/16093c8c9535f7---75329312904.pdfIn PDF document text
    • http://traditionsradio.com/wp-content/plugins/super-forms/uploads/php/files/hr9usn30hufcs7c3712d9kaqm5/95860060707.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d2e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2E4 5780 bytes
SHA-256: 3684d9698de68a067bcab01a1e5460daf1e4a27d43c295b572467717cca81c1d
font_01_sfnt_off0000e68b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE68B 10764 bytes
SHA-256: 80c9e61abb6334644b707dfb3d7076cede67e6a6266e7bdc27e531eed00edfd9